Method of forming manifolds



M y 1933- w. L. ENGHAUSER METHOD OF FORMING MANIFOLDS Original Filed Feb. 20, 1929 INVENTOR x WTTORNEY Patented May 2, 1933 UNITED STATES WINIOBD L. ENGHA'USER, OF LEBANON, OHIO METHOD FORMING MANIFOLDS Original application flied February 20, 1929, Serial No. 841,467.- Divided and this application filed June 2, 1981.

This invention relates to an improved method of manufacturing manifolds and is particularly directe to a method of forming nipple receiving apertures or tap holes in manifolds for use on gas stoves and the like and is divisional of Patent No. 1,813,152, issued July 7, 1931, filed February 20 1929. In formation of these manifolds, it is preferable to use a standard gas pipe, which pipe has a relatively thin wall. The fittings or nipples are screw-threaded into the walls of the pipe. The connections of the nipples or fittings to the manifold must be gas tight and for this reason 1t 1s desirable to have the openings through the wall of considerable length for greater hearing and increased thread length. The normal thickness of the wall of the standard pipe is insuiiicient for the formation of the necessary number of threads in a bore therethrough for a positively rigid connection of the nipple and a gas tight oint It is, therefore, the ob ect of this invention to provide a method of forming tap holes in which the bores are of increased [length over the normal or standard p pe wall thickness for increasing the bearing for the nipple and making it possible to provide an increased number of threads. It

is furthermore provided that the ends of the bosses formed by this method of increasing the length of the tap bores are approximately squared or not as rounded as the bore ends provided b drilling directly through the thin wall 0 the pipe. This ordinarily approximate squaring permits easier starting of the .tool for the thread cutting operation as well as greater ease in startingthe nipples into the threaded bore due to the provision of a more continuous thread. Moreover the joint is stronger when the threads are less broken.

Other objectsand certain advantages will be more fully apparent from a description of the accompanying drawing, in which:

Figure 1 is a diagrammatic view illustrating manifold pipes secured in a work holder, whereby the operation of initially drillin the manifold is performed at one side 0 the Work s pp t and the ap bore Serial No. 541,658.

lengthening operation is performed at the op osite side.

igure 2 is an enlarged transverse section through a pipe manifold illustrating the same a ter the operation of drilling has been performed.

Figure 3 is a sectional view taken similar to Figure 2, but showing the tap bore after it has been lengthened.

Figure 4: is a View taken similar to Figure 3 but illustrating the threads applied to the tag bore.

lgure 5 is a sectional view taken on line 5-5, Figure 3, further illustrating the lengthened bore prior to threading.

Figure 6 is a perspective view of the manifold after the operations of tap bore len honing and threading.

he tap holes of this invention are formed of increased bore length by means of a s inmng or rapidly rotating swaging tool. or centering the spinning tool at the start it has been found desirable to first drill the wall of the manifold prior to the spinning tool operation, this aiding in the centering of the tool and lessening the possibility of damage to the spinning tool which might result due to the length of an operation of swaging the relatively reater mass. Moreover, it has also been ound that when the aperture has been drilled to a predetermined diameter which is carefully calculated, based on the diiference in diameter between the drill and the spinning tool, the proper amount of metal to form a boss or a flange of a given length and thickness is then acted on by the spinning or swaging tool.

It will be understood, however, that the initial operation of drillin is referable although it may not be per orme depending upon the hardness of the pipe and the form of aperture or tap bore desired. For the initial operation of drilling, the pipe may be supported in any desired manner, a preferred apparatus being disclosed in the co-pending application Serial Number 341,467 which relates to a machine for carrying out this method.

As shown diagrammatically inFigure 1, the pipe 10 is. secured between the clamping elements 11 of a work holding device 11 within a work holder 12 of the reversible type having duplicate work holding devices at respectively opposite sides, whereby the holder may be upset after the pgeration to dispose the drilled pipe for e sp' g or swaging operation on the opposite side.

The drill 13 may be of any conventional and is suitably supported toward 1ts outer end for an accurately centered drilling operation by means of a centering bracket 14 and is socketed within a spindle 15. The drawing illustrates a single drill in 15 o ration but it will be understood that a puralityofdrillsmaybeusedtodrilla' lurality of openings 18 simultaneously. lhis also applies to the spinning tools. Each spinning tool 16, socketed in a spindle 17,- has a rounded end for ease and accuracy in centering the same as it is passed into the particular drill hole. The spinnin tool, as it is passed through the wall of t e manifold, is rotating at a high rate of 35 speed and immediately upon contact therewith heats the metal about the drill hole to a forming heat and swages or ins the same partly toward the interior an partly toward the exterior of the manifold. Since the metal is heated and the swa or deforming takes place rapidly un er centrifugal force, there is little tendency to depress the wall of the pi inwardly and a smooth integral sleevee portion, including inwardly and outwardly formed bosses 19 and 20 for the opening, is provided. The rotating tool of highly hardened steel is passed through or penetrates the wall of the pipe with substantially no resistance since the friction between the tool and metal induces heat almost instantly and the tool meltsits way through either the blank wall or the previously apertured wall. No heavy inward or longitudinal tool feeding pressure is ry since the tool passes easily through the softened wall and one pass of the tool is suflicient for the formation of the im roved tap hole or sleeve.

Ks stated, the metal is heated to a red 15 heat by the spinning tool contacting the metal rotating at high speed which result occurs best due to the friction induced by a dry contact. The drilled hole (see Figure 2) is of smaller diameter than the predetermined size of the finished tap hole and the difference between these diameters is computed to furnish enough metal mass for a sleeve of sufiicient length.

More specifically, describing the action of the spining tool, there is very little longitudinal pressure, the tendency of the spinning action being to displace or force the metal radiall or tangentially from the spinning tool. his permits the back spinning 66 of the metal in the formation of an outer flange. The metal is easily spun and s read along the tool in the formation of the doses insboth dhirections. 1

incetesw ressuresa iedare equal in all that is tr ziiisversely and longitudinally as induced radially or centrifugally of the spinning tool, the swaging action takes place unevenly as in the following manner in view of the fact that a curved metal plate is being acted u 11. There is displacement of more metal allfng the transverse edges of the opening on the exterior of thepipe than on the longitudinal edges, while the opposite is true as to the interior of the pipe. This will be apparent from Figures 3 and 5. This results in the formation of flanges which have approximately squared ends or ends which are not formed on the same curv'e'as the curvature of the wall being of a curve in between this curve and a straight line. The building up or swaging of the metal to the transverse sides of the flanges exteriorly and the longitudinal sides of the flanges internally occurs largely because there is less support at these points due to the curvature, of the wall and less resistance to the swaging action of the tool. The tool having a straight portion traversing the pipe wall forms a straight finished bore for threading.

After the manifolds are taken from the machine, the tap openings are screw-threaded as shown at 21 in Figure 4 and it is apparent therefrom that a greater number of threads may be applied to the sleeve-like tap hole than could be applied to the normal wall thickness of the pipe. Moreover, the

ends of the flanges or the sleeve being nearer a straight or squared condition, there is greater ease in starting the threads. and there are less broken threads than there would be if the threads were applied t0 an opening through the normally curving wall ofdthe pipe or a boss sharply curved at its en Having described my invention. I claim:

1. The process of forming a sleeve opening in thin wall malleable iron pipe consisting of paxing a rapidly rotating spinning tool through the wall thereof for simultaneously frictionally generating red heat in the metal of the pipe adjacent the tool, thereby causing the metal to become plastic, and displacing the metal in both directions along the tool.

2 The process of forming a sleeve opening in thin wall malleable pipe consisting of initially forming an aperture in the fall of the pipe and thereafter passing a blunt end straight rapidly rotating spinning tool of greater diameter than the aperture through the aperture for simultaneously frictionally generating red heat in the metal of the pipe adjacent the tool rendering the metal plastic and displacing the metal in both directions along the tool.

3. The process of forming a sleeve opening in thin wall malleable pipe consisting of passin a rapidly rotating spinning tool through t e wall thereof for simultaneously frictionally generating a red heat in the metal of the pipe adjacent the tool, rendering the metal plastic and displacin the metal in both directions along the tool orming a sleeve opening having substantially squared ends.

4. The process of forming in thin wall malleable pipe a sleeve of a length greater than the t ickness of the pipe, the process comprising, melting an opemng in the wallof said pipe with an elongated blunt tool moving longitudinally along its own axis and in a state of rotative motion adapted to generate red heat in the metal adjacent the tool. 7

5. The process of forming in thin wall malleable pipe a sleeve of a length greater than the thicknes of the pipe, the rocess comprising, penetrating the wallpf sa1d pipe with an elongated blunt tool moving longitudinally on its own axis, and ossessed of 'a rotative motion adapted to so en the pipe metal about the tool.

6. The process of forming in thin wall malleable ipe a sleeve of a length greater than the t 'ckness of the pipe, the process comprising, rendering the metal of the pi ewall. plastic and displacing it simultaneous y by means of an elongated blunt tool moving longitudinally on its own axis and generating red heat in the metal about the tool upon contact with the pipe by virtue of its own rotative motion.

7. The process of forming in thin wall pipe a sleeve of a length greater than the thickness of the pipe, the process comprising, penetrating the pipe with an elongated tool moving longitudinally on its own axis and at a high speed rotatively and enerating red iiealt by friction in the metal adjacent the 8. The process of forming in thin wall pi e a sleeve of a length greater than the thic ness of the pipe, the process comprising, penetratipg the pipe wall with an elongated tool moving lon 'tudinally on its own axis and possessed o suflicient rotative motion to melt its way therethrough.

In witness whereof, I hereunto subscribe my name.

WINFORD L. ENGHAUSER. 

